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Computer Mouse/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Tim is typing on a computer, and Moby is looking at the monitor. MOBY: Beep? TIM: I'm, ah... writing a report on waves. Moby shows Tim a letter. MOBY: Beep. TIM: Okay, but I gotta finish this paper at some point. Tim reads from the typed letter. TIM: Dear Tim and Moby, How does the click of a computer mouse activate computer programs? From, Zelda. Hey, where'd my mouse go? Moby holds a small rat. MOBY: Beep. TIM: You silly robot. RAT: I'm not a mouse; I'm a rat. TIM: There are actually a bunch of different mouse types, but one of the most common is called the mechanical or ball mouse. A mechanical mouse looks something like this. It has at least one button, and a spherical roller ball on its bottom. An image shows the top, bottom, and side of a mechanical mouse. Arrows point to the ball on the bottom and the button on the top. TIM: When you move your mouse, the roller ball spins and transfers its movements to two slotted wheels inside the casing. An animation shows how the ball works inside the mouse and illustrates the other parts and functions as Tim describes them. TIM: Each wheel incorporates a light emitter, called a light-emitting diode or LED, and a light receiver, called a photodiode. The LED shines a light through slots in the wheels to the photodiodes. As the ball spins, the wheels spin along with it, and the slots in the wheel cause the lights to flash depending on how fast the ball is moving. This creates a pair of pulsing electrical signals that are sent to your computer. An animation traces the path of the mouth movement on a grid as Tim describes how the computer interprets the signals. TIM: The computer interprets these electrical signals as a pair of coordinates, one showing up and down, and the other showing left and right. An animation shows a mouse arrow moving. TIM: It can then calculate the mouse's change in position. When you move your mouse, the pointer on your screen moves along with it, mirroring your movements. A split screen shows a computer screen with the mouse's pointer coordinated to an animation of a hand moving the mouse. MOBY: Beep. TIM: Right. In 1999, optical mice were introduced. An image shows an optical mouse. TIM: These mice have fewer moving parts, so there's less wear and tear, and they don't have a ball, so dirt can't get in and mess with the sensors. In an optical mouse, a light-emitting diode bounces its beam off of any surface. Images and animations illustrate how reflected light works with other parts within the mouse as Tim describes it. TIM: The reflected light bounces from the surface back to the mouse, where a special sensor picks it up and converts it into an image. The light and the sensor combine to take 1,500 tiny pictures every second. The sensor shows each picture to a processor, which analyzes the series of images to detect how far the mouse has moved. Images and animations show how the mouse communicates with the computer as Tim continues. TIM: The processor sends this information back to the computer, which moves the cursor on the screen. This happens more than one hundred times every second, so it looks like the cursor is moving very smoothly across your computer desktop. MOBY: Beep. TIM: Right, there are some other devices that work as mice, too. A trackball is essentially an upside-down mouse, with the ball on top. With a trackpad, you can use your finger to move the pointer. And some laptops have this little knobby thing in the keyboard that you control the pointer with. Images show the devices Tim describes. TIM: Hot spots like icons and buttons and links are areas of your computer screen that have operations assigned to them. Moby uses the mouse at the computer. An animation shows the cursor moving around the screen to a file called dancingmogy that Moby double clicks. TIM: That way, you can use the mouse to control the computer. The file opens to show Moby dancing. Moby double clicks and opens Tim's Waves Paper file. Moby clicks on the close file button, a message appears warning that the document has not been saved and if it is closed, it will be lost forever. The button choices are OK or cancel. Moby chooses OK. The screen is blank for two seconds. TIM: Don't tell me you just erased my paper. Moby waves his hand around his head. MOBY: Beep. TIM: You'll retype it? MOBY: Beep. TIM: Okay. The screen reads "Later that night…" and Moby is heard typing. TIM: Wow, you type fast. Moby continues to type rapidly. Tim's paper is shown. Moby is typing gibberish. Category:BrainPOP Transcripts